Primarily a workbench for exploring how the PC platform works
mkcd - build into a CD ISO image (latest development) mkflop - build into a FAT12 floppy image (first development) mkhd - build into a hard drive image (side development) osinfo - a CD image which just dumps configuration information
Of possible use to other people is my bootloader: one sector (512B), sets the video mode, and readies the kernel for 64 bit mode.
The best source I've found for OS development is: http://wiki.osdev.org/Main_Page
I use Bochs for testing the os image (see the OSDev Bochs page).
apt-get install bochs
probably won't be enough.
You'll probably need: bochs-x, bochsbios, vgabios
When you first run bochs, make sure to enable a 64 bit CPU, and set CD
boot (and save the config)
cd mkcd
make
cp test.iso <bochs area>
I use Bochs magic instructions (xchg bx,bx) for debugging. You should use them too. You will need to continue several times to reach the end (jmp end).
cd twoStage
make
qemu-system-x86_64 -hda twoStage/bochs.img